M3: Chapter 7 Notes
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Academic
Chapter 7 Notes
Percents
Name____________________Pd.____
M3: Chapter 7 Notes
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Vocabulary Word List
Sections 7.1-7.7
Section 7.1:
 Percent
Section 7.2:
 percent proportion
Section 7.3:
 percent equation
Section 7.5:
 percent of change
 percent of increase
 percent of decrease
Section 7.6:
 markup
 discount
Section 7.7:
 interest
 principal
 annual interest rate
 simple interest
 balance
M3: Chapter 7 Notes
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Section 7.1: Percents and Fractions
Learning Goal: We will use a fraction to find the percent of a number.
Vocabulary:
 Percent –
Example 1: Writing Percents as Fractions, Fractions as Percents
Write the percent as a fraction in simplest form.
a. 80%
b. 61%
c. 29%
d. 45%
Write the fraction as a percent.
a.
27
50
ON YOUR OWN:
b.
13
25
c.
7
10
d.
3
5
M3: Chapter 7 Notes
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Example 2: Writing a Probability as a Percent
ON YOUR OWN:
An airport security screener searches the luggage brought to the
ticket counter by 3 of every 10 passengers. If you are one of the
persons in a group of 10 passengers, what is the probability that you
will be chosen to have your luggage searched? Write your answer as a
percent.
Example 3: Finding a Percent of a Number
Ninety percent of the flights that left the Pittsburgh airport
yesterday departed on time. If there were 150 flights from the
airport yesterday, how many of them departed on time?
M3: Chapter 7 Notes
ON YOUR OWN:
EXTRA PRACTICE:
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M3: Chapter 7 Notes
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Section 7.2: Percents and Proportions
Learning Goal: We will use proportions to solve percent problems.
Example 1: Finding a Percent
a. What percent of 15 is 2?
ON YOUR OWN:
b. What percent of 7 is 4?
M3: Chapter 7 Notes
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Example 2: Finding a Part of a Base
a. What number is 45% of 400?
b. What number is 24% of 200?
Example 3: Finding a Base
A python consumes a meal that weighs 3 pounds. This weight is 5% of
the python’s weight before the meal. How much did the python weigh
before eating the meal?
ON YOUR OWN:
M3: Chapter 7 Notes
PERCENT SUMMARY:
EXTRA PRACTICE:
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M3: Chapter 7 Notes
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Section 7.3: Percents and Decimals
Learning Goal: We will use decimals to solve percent problems.
Example 1: Writing Decimals as Percents
Write the decimal as a percent.
a. 0.62
b. 1
c. 2.3
d. 0.021
f. 6
e. 1.55
Example 2: Writing Percents as Decimals
Write the percent as a decimal.
a. 75%
b. 0.4%
c. 168%
d. 54%
f. 220%
ON YOUR OWN:
e. 0.95%
M3: Chapter 7 Notes
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**You can write a fraction as a percent by first writing the fraction as
a ____________________.
Example 3: Writing Fractions as Percents
Write the fraction as a percent.
a.
3
8
b.
5
3
c.
1
6
d.
9
5
e.
7
8
f.
5
12
Example 4: Finding a Percent of a Number
About 5.2% of the 8460 visitors to a tropical resort last month
registered to try parasailing. Approximately how many visitors
registered for parasailing?
ON YOUR OWN:
M3: Chapter 7 Notes
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Section 7.4: The Percent Equation
Learning Goal: We will use equations to solve percent problems.
**We can use the proportion from Section 7.2 to find the percent
equation.
a
p

b 100
Example 1: Finding a Part of a Base
What number is 65% of 84?
ON YOUR OWN:
M3: Chapter 7 Notes
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Example 2: Finding a Commission
ON YOUR OWN:
A hotel charges a couple $1500 to hold a small wedding ceremony in
their garden. The couple must pay the hotel 12.5% of the charge as a
deposit. How much is the deposit?
Example 3: Finding a Percent
a. What percent of 70 is 245?
b. What percent of 25 is 60?
Example 4: Finding a Base
A tourist dining at an outdoor restaurant in the Caribbean counts 6
iguanas in cages on the restaurant’s patio. A waitress informs the
tourist that these 6 iguanas represent 30% of the iguanas living on the
restaurant’s property. How many iguanas are there at the restaurant?
M3: Chapter 7 Notes
ON YOUR OWN:
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M3: Chapter 7 Notes
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Section 7.5: Percent of Change
Learning Goal: We will find a percent of change in a quantity.
Vocabulary:
 Percent of change – a percent that indicates how much a quantity
increases or decreases with respect to the original amount
 Percent of increase – the percent of change in a quantity when
the new amount is greater than the original amount
 Percent of decrease – the percent of change in a quantity when
the new amount is less than the original amount
Example 1: Finding a Percent of Increase
At its first visit to a veterinarian, a puppy weighed 28 pounds. Three
months later, the puppy weighed 46 pounds. Find the percent of
increase in its weight.
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ON YOUR OWN:
Example 2: Finding a Percent of Decrease
a. Find the percent of decrease
b. Find the percent of decrease
from 250 to 145.
from 512 to 320.
ON YOUR OWN:
Finding a New Amount:
M3: Chapter 7 Notes
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Example 3: Using a Percent of Increase
ON YOUR OWN:
Example 4: Finding a New Amount
Last month, a restaurant charged $12.95 for a seafood pasta dinner.
This month, the owner had new menus printed, with all dinner prices
increased by 12%. What is the new price for a seafood pasta dinner?
EXTRA PRACTICE:
M3: Chapter 7 Notes
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Section 7.6: Percent Applications
Learning: We will find markups, discounts, sales tax, and tips.
Vocabulary:
 Markup – the increase from the wholesale price (original) of an
item to the retail price (new)
Example 1: Finding a Retail Price
ON YOUR OWN:
Find the retail price of a collectible figurine with a wholesale cost of
$12 that is marked up 75%.
 Discount – the decrease from the original price of an item to the
sale price
Example 2: Finding a Sale Price
Mason buys a suit that is on sale for 20% off the original price of
$180. What is the sale price?
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You buy an electronic organizer that is on sale for 15% off the original
price of $25. What is the sale price?
ON YOUR OWN:
Example 3: Using Sales Tax and Tips
The bill for your restaurant meal is $22. You leave a 15% tip. The
sales tax is 6%. What is the total cost of your meal?
ON YOUR OWN
The bill for a family’s meal at a restaurant is $68. They leave a 15%
tip. The sale tax is 6%. What is the total cost of their meal?
Example 4: Finding an Original Amount
A dress shop marks up the wholesale price of a prom dress by 115%.
The retail price is $180. What is the wholesale price of the dress?
M3: Chapter 7 Notes
ON YOUR OWN:
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M3: Chapter 7 Notes
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Section 7.7: Simple Interest
Learning Goal: We will calculate interest earned and account balances.
Vocabulary:
 Interest –
 Principal –
 Simple interest –
 Annual interest rate –
Example 1: Finding Simple Interest
Find the simple interest earned on $500 after 5 years in a money
market account paying 5%.
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ON YOUR OWN:
A $1000 bond earns 6% simple annual interest. What is the interest
earned after 4 years?
 Balance –
Example 2: Finding an Account Balance
You deposited $200 into a bank account that earns simple annual
interest. If the annual interest rate is 4%, how much money will you
have in your account after 3 years?
ON YOUR OWN:
Grace wins the IMS American Idol competition with a first place prize
of $750. She decides to deposit the money into a savings account that
earns 3.5% simple annual interest. How much money will she have in
the savings account after 6 months? (Hint: t must be in years.)
Example 3: Finding an Interest Rate
Jose deposits $2000 of his tax refund into an account that earns
simple annual interest. After 6 months, the balance is $2040. Find
the annual interest rate.
M3: Chapter 7 Notes
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ON YOUR OWN:
You deposit $750 into an account that earns simple annual interest.
After 3 years, the account balance is $930. Find the annual interest
rate.
EXTRA PRACTICE: